The present invention relates to a network management system and a method of managing a network which is for use in a network using SNMP (Simple Network Management Protocol) between a network management device for managing the network and a management object device connected to the network management device through the network to be managed thereby, in particular to a network management system and a method of managing a network which are capable of reducing load caused by SNMP packets flown on the network between the network management device and the management object device.
SNMP is one of protocols that are used in a system for carrying out, through an Internet, operations of managing a condition of a device constituting the Internet, such as a router, or the like.
In the interim, Internet Protocol (IP) has two protocols as protocols of a transport layer in a packet transfer. Namely, the two protocols are UDP (User Datagram Protocol) and TCP (Transmission Control Protocol). UDP is a connection-less type protocol for providing the function of IP to an upper layer substantially as it stands, compared with TCP that is a connection type protocol having a re-transmission function and a flow control function.
SNMP protocol for managing operations is originally operable upon the connection-less type UDP/IP in view of reducing load on the network. Under the situation, when managing data are transmitted by BER (Basic Encoding Rules) encoding method, an object identifier (ID) portion is added to each managing item. However, information is transferred inefficiently, since the object identifier (ID) portion comes up to ten and several bytes. As a result, as will later be described more in detail, load on the network becomes large in a conventional network management system, when many traps are generated from the management object device on the network between the management object device and the network management device. Further, load on the network also becomes large, when many “Get-request”, “Set-request”, and the like are issued from the network management device to the management object device on the network. Consequently, it is feared that the network is suppressed by the large load in the conventional network management system.